The present invention relates to a bone surgery holding apparatus for a fixing rod, with a bone plate which can be fastened to the bone, a receiving device for the fixing rod, and a fixing device which secures the fixing rod in the receiving device; the bone plate can be fixed to the bone independently of the receiving device.
EP-A-443 894 discloses a bone plate, which can be fastened, for example to a vertebra, via two bone screws. One of the bone screws has a forked head, into which a rod can be inserted and fixed. The bone plates can be connected directly to each other via a further rod. A correction of the bone plates embodied in this way is either impossible or very difficult to achieve, since there are no arrangements made for fastening a correction rod. In addition, after fixing, the holding apparatuses must be coated with pleura.
It has been found that because of the relatively high construction of this known holding apparatus, under the circumstances, a coating with pleura is either impossible or very difficult to achieve. In many cases synthetic pleura is required for the coating, which is not universally available and besides is very costly.
U.S. Pat. No. 4,289,123 discloses another holding apparatus, which can be placed on vertebrae. This holding apparatus is used as a rule to bridge individual vertebrae, by attaching bone plates to the neighboring vertebrae and connecting them to each other via two threaded rods. From a biomechanical point of view, a holding apparatus of this kind is extremely unstable and costly to fasten and install.